Sidney Lumet was undoubtedly an American film master whose body of work has been justly praised but if there’s one film of his that is an undeservedly under-appreciated masterpiece, it has to be his 1972 psychological police procedural, The Offence. Adapted from his own play by scriptwriter John Hopkins, this is the story of a search for a serial child rapist and the abrupt mental unraveling of 20-year police veteran Detective Sergeant Johnson (Sean Connery) after the arrest of prime suspect Kenneth Baxter (Ian Bannen).

In its early going, the film has the feel of a typical police procedural, albeit one with that brilliant super-slow 70’s film pacing that is sadly long gone. At a crawl, we’re introduced to Johnson in the midst of an attempt to catch a serial rapist who has already attacked three girls in this ugly, drab modern London suburb. It’s clear from the beginning that Johnson is a cynical, bitter, no-nonsense detective who has seen it all and doesn’t have much use for the limitations of rules and regulations. When a fourth girl is abducted, it’s Johnson who finds the girl in the woods where she was left after being molested. Soon a suspect is arrested and brought in for questioning.

When the mild interrogation techniques employed by several officers don’t produce results, Johnson soon takes over and employs a much harsher method. The film opens with a subtle reference to this interrogation sequence that is only understandable as the film progresses and the film closes with the full reveal of what took place between Johnson and Baxter during the intense interrogation. In between the film jumps between events past and present, revealing little about Baxter’s possible crimes or motivations but pulling back layer after layer from Johnson’s gruff shell, revealing a deeply flawed, cracked creature within. The film’s three brilliant key sequences all involve extended one-on-one exchanges: between Johnson and his wife (Vivien Merchant), between Johnson and his superior police officer Lieutenant Cartwright (Trevor Howard), and the interrogation of Baxter by Johnson.

It’s not until Johnson returns home from his bloody interrogation of Baxter that his own darker impulses and unraveling sanity begin to become clear to the viewer. In his bullying psychological undressing of his wife, a painful-to-watch but brilliantly acted scene on the part of both actors, it becomes clear that all the crime and suffering he’s borne witness to in his twenty-year police career has badly scarred him. But it also starts to become clear that this is a man who has long secretly harbored his own sadistic impulses, a man who is both repulsed by the things he’s seen and attracted to them, a man who relishes going after men who commit terrible acts against girls, acts that he himself fantasizes about committing.

If Connery has ever delivered a finer, more intense performance, I don’t know what it is. It was a bold move on his part to take such a role, evidently a project that he convinced Lumet to direct. And it is matched by the performance of Ian Bannen. The film’s stage roots feel clear in the extended interrogation sequences; repeatedly we are witness to two actors on a stage brilliantly plying their craft, slowly circling around one another looking for an opening, often making it impossible to tell who is the interrogated and who is the interrogator. As the probably-guilty Baxter says to Johnson at one point, “Don’t beat me for thoughts in your head, things you want to do.” But Johnson, having lost his ability to any longer contain his inner turmoil and repressed darker impulses, proceeds to do just that.